A prior art method of making a floorboard in the way stated above will now be described in more detail with reference to FIGS. 1-4 which illustrate a prior art floorboard of the type in which the method according to the invention can advantageously be used. FIG. 1 is a top plan view of the prior art floorboard, while FIGS. 2 and 3 illustrate the floorboard in cross-section and in longitudinal section respectively. FIG. 4 is a partial cross-sectional view and illustrates two floorboards according to FIGS. 1-3 connected to each other.
The floorboard 1 shown in FIGS. 1-3 is conventionally elongated and rectangular in shape. Floorboards of this type usually have a length of 1-2.6 m and a width of 100-200 mm. The floorboard 1 has at its four side edges connecting means 2, 3, 4, 5, which are arranged, when laying a floor, to cooperate with corresponding connecting means of other identical floorboards 1 in order to interconnect them. The floor consists of a plurality of neighbouring parallel rows of juxtaposed floorboards 1, the floorboards 1 of one row being interconnected short side to short side and the floorboards 1 of neighbouring rows being interconnected longside to longside, as shown in FIG. 4.
The connecting means 2-5 consist of a first pair of connecting means 2, 4, which consists of a female connecting means 2, which extends along one longitudinal side edge 6 of the floorboard 1, and a male connecting means 4, which extends along the other longitudinal side edge 7 of the floorboard 1, and a second pair of connecting means 3, 5, which consists of a female connecting means 3, which extends along one short side edge 8 of the floorboard 1, and a male connecting means 5, which extends along the other short side edge 9 of the floorboard 1.
The female connecting means 2, 3 in each pair of connecting means 2, 4 and 3, 5 has a first connecting part 10, which projects laterally from the side edge 6, 8 and extends along the same at a level below the upper surface of the floorboard 1. The first connecting part 10 has an upward open groove 11, which extends along the first connecting part.
The male connecting means 4, 5 in each pair of connecting means 2, 4 and 3, 5 has a second connecting part 12, which projects laterally from the side edge 5, 7 and extends along the same. A downward and laterally open longitudinal recess 13 is formed under the second connecting part 12.
For interconnection of two floorboards 1, the second connecting part 12 of the associated male connecting means 4 or 5 of one floorboard 1 is inserted in the groove 11 in the first connecting part 10 of the associated female connecting means 2 or 3 of the other floorboard 1, the first connecting part 10 being received in a corresponding recess 13 in the second connecting part 12, as shown in FIG. 4 for the connecting means 2 and 4 at the longitudinal side edges of the floorboards 1.
As is evident from FIGS. 2-4, the floorboard 1 is made up of three layers, viz. a carrier layer consisting of a bottom veneer layer 14 and an intermediate layer 15, and an upper wear layer 16. As is also illustrated, the wear layer 16 has an edge bevel 17 at each of its longitudinal side edges. The edge bevels 17 have an aesthetic purpose since they are to give the floor laid of the floorboard 1 a board-like structure and delimit the individual floorboards from each other in the lateral direction. The wear layer 16 provided with edge bevels 17 is varnished.
In the prior art method of making a floorboard of this type, one starts from a raw board, which is substantially rectangular in cross-section and which comprises a carrier layer 14, 15 and, applied to top thereof, a wear layer 16. In a first working step, the raw board is profiled for forming of connecting means 2-5 in the carrier layer 14, 15, at the longitudinal side edges as well as at the short side edges, and for bevelling of the wear layer 16 at its two longitudinal side edges. In a second working step, the profiled raw board is varnished by being passed on a conveyor belt through a plurality of varnishing stations and hardening stations, located between these varnishing stations, for hardening, for instance UV hardening, of the varnish or paint that has been applied. In each varnishing station, there are arranged an applicator roll for applying varnish/paint to the wear layer 16 and its edge bevels 17 and a counter roll which is placed under the conveyor belt.
This process of varnishing suffers, however, from the drawback that the varnish/paint is not applied in a homogeneous way to the wear layer 16, especially its edge bevels 17. In particular, there are difficulties in the corner area where the two male connecting means 4 and 5 of the floorboard 1 meet each other. In an attempt at eliminating these difficulties, separate edge bevel varnishing has been performed by means of applicator rolls in an additional varnishing plant between the two working steps described above, said application rolls being inclined according to the respective edge bevels. However, nor has this provided satisfactory varnishing results since a varnish/paint layer edge was obtained in the transition between the horizontal part of the wear layer 16 and the edge bevels 17. Moreover, the method is made more complicated and expensive by this additional varnishing plant.